CN109650547B

CN109650547B - Method for controlling growth of blue algae in water area by utilizing eucalyptus

Info

Publication number: CN109650547B
Application number: CN201910041916.4A
Authority: CN
Inventors: 郑正; 赵薇; 罗兴章; 何坚; 张威振; 徐力
Original assignee: Fudan University
Current assignee: Fudan University
Priority date: 2019-01-15
Filing date: 2019-01-15
Publication date: 2020-10-30
Anticipated expiration: 2039-01-15
Also published as: US11760671B2; US20220041482A1; WO2020147201A1; CN109650547A

Abstract

The invention provides a method for controlling the growth of blue algae in a water area, which relates to the field of surface natural ecology restoration and protection, and constructs an ecological water area water treatment system taking microorganisms, plants, animals, fillers and the like as main elements by constructing a novel ecological slope protection at a land-water staggered zone at the bank side of the water area and planting eucalyptus in the water area and/or along the bank of the water area, thereby effectively realizing the efficient nitrogen and phosphorus removal of the water area, controlling the spread of the blue algae and improving the water environment quality.

Description

Method for controlling growth of blue algae in water area by utilizing eucalyptus

Technical Field

The invention relates to the field of ecological restoration and protection of surface nature, in particular to a method for controlling the growth of blue-green algae in a water area.

Background

The outbreak of algae, especially blue algae, caused by eutrophication has become a worldwide problem. The burst of blue algae not only causes economic loss in aquaculture industry, but also causes system unbalance, damages ecological landscape of water areas and harms human health. Therefore, the search for relevant solutions has always been a scientific frontier.

Through research, the blue algae outbreak is self-maintenance emergency reaction of the lake on the over-nutrition salt, and the nutrition salt is absorbed in the blue algae body during the blue algae outbreak. But after the outbreak period, the nutritive salt in the decaying blue algae returns to the lake again. Therefore, only inhibiting and killing the blue-green algae is always the temporary solution but not the permanent solution on the aspect of controlling the burst of the blue-green algae, and the correct choice for long-term treatment is to accelerate the biogeochemical cycle of nutrient salts in lakes.

The traditional emergency algae removal technology can be roughly divided into three types, namely physical technology, chemical technology and biological technology, wherein the more common technology comprises chemical algaecide adding, ultrasonic treatment, flocculation, fishing and the like. The methods not only have a series of problems of high cost, large operation difficulty coefficient, secondary pollution and the like, but also can only temporarily inhibit blue algae outbreak and cannot fundamentally solve the problem of water eutrophication. Therefore, the seeking of the cyanobacterial bloom control method which is eco-friendly, low in cost and capable of pumping out firewood and stopping boiling remains a key problem to be solved urgently in the water environment protection research.

Disclosure of Invention

In order to overcome the defects, the inventor of the invention carries out intensive research and provides a method for controlling the growth of blue-green algae in a water area, which constructs an ecological water area water treatment system taking microorganisms, plants, animals, fillers and the like as main elements by constructing a novel ecological slope protection at a land-water staggered zone on the shore of the water area and planting eucalyptus in the water area and/or along the shore of the water area, thereby effectively realizing the efficient nitrogen and phosphorus removal of the water area, controlling the spread of the blue-green algae and improving the water environment quality, and thus the invention is completed.

The invention aims to provide the following technical scheme:

(1) a method of controlling the growth of blue algae in a water area, the method comprising: planting trees in and/or along the shore of the watershed water;

preferably, the tree is eucalyptus, pollutants are absorbed or fixed and removed through the root system of the tree, and the growth of blue algae is inhibited.

In a preferred embodiment, the method further comprises collecting the eucalyptus leaves, and adding the eucalyptus leaves or the eucalyptus leaves leaching solution to the watershed water; wherein the folium Eucalypti Globueli leaching solution is water leached product.

In a preferred embodiment, the method further comprises constructing an ecological slope protection 100 at the land-water interlaced zone on the bank side of the basin water, wherein the slope body of the ecological slope protection 100 extends into the basin water, the surface layer of the ecological slope protection is paved with a soft body row 110, the lower part of the soft body row 110 is an ecological filter tank 120, the ecological filter tank 120 isolates the basin water through a sealed tank body, the ecological filter tank 120 is filled with a filler layer and a support layer 125, the basin water is introduced into the ecological filter tank 120, the introduced basin water is subjected to pollutant treatment through the filler layer to reduce the eutrophication degree of the basin water, the filler layer is supported through the support layer 125, and the ecological slope protection 100 is formed by the treated basin water through the support layer 125.

The method for controlling the growth of blue algae in the water area by using the eucalyptus provided by the invention has the following beneficial effects:

(1) the ecological slope protection surface layer is covered with a soft row composed of a plurality of layers of composite materials, the interior of the ecological slope protection surface layer is a biological filter, and the ecological slope protection surface layer is formed by grading fillers with different particle sizes, so that an ecological water treatment system taking microorganisms, plants, animals, fillers and the like as main elements is constructed;

(2) the sewage ecological treatment system is designed according to ecological functions of eating organic matters, improving the soil ventilation and water permeability, realizing the synergistic effect of the earthworms and microorganisms and the like, and has a good treatment effect on non-point source pollution;

(3) the ecological slope protection can be transformed on the basis of the original slope protection, so that the occupation of land resources is greatly reduced;

(4) the ecological slope protection is a modularized, large-scale and serialized device system, is easy for industrial production, and is low in construction cost and operation cost and easy to maintain; and the sewage is respectively treated by different layers of ecological filter tanks through different water taking points according to the difference of the water quality at the center of the basin and the water quality at the bank, so that the sewage comprehensively reaches the standard of high effluent water quality;

(5) the aeration pipe is arranged, so that the problem of oxygenation of the watershed water under the ecological slope protection is effectively solved, and survival of aerobic organisms, removal of organic pollutants, nitrogen and phosphorus removal in the watershed water are facilitated;

(6) the eucalyptus is specifically selected as the greening tree species in the watershed water and/or on the watershed water coasts, the water quality can be purified through the root system function, allelochemicals generated in the growth process can effectively inhibit the growth of algae, and no secondary pollution is generated;

(7) the construction of the regulating tank plays a role in regulating and controlling the blue algae fertilization, the flowing water retreatment and allelochemical release, and is an effective auxiliary means for controlling the blue algae in the flowing water.

Drawings

Fig. 1 is a schematic sectional view of an ecological slope protection according to an embodiment of the present invention;

fig. 2 shows a schematic arrangement diagram of watershed water-ecological slope protection-eucalyptus in one embodiment of the invention;

FIG. 3 is a schematic diagram of a modular ecological filter according to an embodiment of the present invention;

fig. 4 shows a schematic view of a modular ecological slope protection structure in one embodiment of the present invention;

FIG. 5 is a graph showing the result of blue algae density and blue algae inhibition when the leaching solution is added in Experimental example 1 to make the concentration of the leaching solution in the algae solution reach 100mg (leaf dry weight)/(L algae solution);

FIG. 6 is a graph showing the result of blue algae density and blue algae inhibition when the leaching solution is added in Experimental example 1 to make the concentration of the leaching solution in the algae solution reach 200mg (leaf dry weight)/(L algae solution);

FIG. 7 shows the cyanobacteria density, soluble organophosphorus SPR, nitrate nitrogen NO in the cocultivation of cyanobacteria and Eucalyptus seedlings in Experimental example 2₃ ^-And N change results are shown schematically.

The reference numbers illustrate:

100-ecological slope protection;

110-soft body row;

120-ecological filter chamber;

121-a soil layer;

122-a conditioning layer;

123-biological layer;

124-ecological layer;

125-bearing layer;

130-water distribution pipe;

140-an aerator pipe;

150-a drain pipe;

210-a fermentation tank;

220-a sedimentation tank;

230-extraction cell.

Detailed Description

The present invention will now be described in detail by way of specific embodiments, and features and advantages of the present invention will become more apparent and apparent from the following description.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

As shown in FIG. 1 and FIG. 2, the object of the present invention is to provide a method for controlling the growth of blue algae in a water area, which comprises:

an ecological protection slope 100 is constructed at a land-water staggered zone on the bank side of the basin water, a slope body of the ecological protection slope 100 extends into the basin water, a soft body row 110 is laid on the surface layer of the ecological protection slope, an ecological filter tank 120 is arranged at the lower part of the soft body row 110, the ecological filter tank 120 isolates the basin water through a sealed tank body, a filler layer and a bearing layer 125 are filled in the ecological filter tank 120, the basin water is introduced into the ecological filter tank 120, pollutant treatment is carried out on the introduced basin water through the filler layer, the eutrophication degree of the basin water is reduced, the filler layer is supported through the bearing layer 125, and the ecological protection slope 100 is produced in the treated basin water through the bearing layer 125;

and planting trees in the watershed water and/or the watershed water along the shore, absorbing or fixing the pollutants through root systems, and inhibiting the growth of blue algae.

According to research, the invention discovers that the algae control of the plants is a method with good ecological safety and good application prospect. The plant has large individual and long life, and the nutrient salt such as nitrogen, phosphorus and the like is more stable to store in the plant body than algae. The more the number and the types of the plants in the watershed water are, the stronger the self-cleaning capability is. However, in the watershed water with extremely serious water eutrophication in China, almost no other plants except algae exist. Thus, it is necessary to perform the reconstruction by human means.

In a preferred embodiment of the invention, a tree, preferably a eucalyptus tree, is planted in and/or along the shore of the watershed water.

Although other aquatic plants and tree species have the same denitrification and dephosphorization effects, through a great deal of experimental research, the inventor finds eucalyptus to be the preferred tree species, which has the following characteristics:

(i) the eucalyptus can generate exclusive secondary metabolites, namely allelochemicals, which are rich in variety (water-soluble allelochemicals separated from the eucalyptus body such as phenolic compounds including ferulic acid, coumaric acid, caffeic acid, eucalyptol, gallic acid, quaternary bean acid, chlorogenic acid and the like, volatile allelochemicals such as pinene, homoene, non-limonene, cineol and the like), and the synergistic effect of various allelochemicals is good in algae inhibition specificity, and compared with plants with allelochemicals such as barley straws, foxtail, bitter herbs and the like, the plant effect is strong, the growth of algae can be effectively inhibited, and no secondary pollution is generated;

(ii) the eucalyptus grows fast, the demand of nutrient salts (nitrogen and phosphorus) is far greater than that of common plants, the biogeochemical cycle of the nutrient salts of the watershed water is fundamentally accelerated, and the blue algae outbreak condition is controlled;

(iii) eucalyptus grows fast, the life cycle is relatively short in trees, nutrient salts can be moved out of water bodies conveniently, the wood quality is good, the eucalyptus is often used for papermaking, the social demand is large, and the overall economic benefit is high.

By combining the three characteristics, the eucalyptus is planted on the bank of the eutrophic water body with water bloom outbreak or in the water body, and when the eucalyptus is in the water body, a part of the eucalyptus is ensured to be above the water surface (can contact the air), and a part of the eucalyptus is below the water surface.

In a preferred embodiment, the eucalyptus leaves are collected and the eucalyptus leaves or the eucalyptus leaf extract is added to the watershed water. Wherein the folium Eucalypti Globueli leaching solution is obtained by water leaching, and the leaching manner comprises ultrasonic leaching and fermentation leaching.

In the present invention, the eucalyptus is not limited, and may be eucalyptus grandis, eucalyptus congo 12, eucalyptus grandis, etc.

In the present invention, a plurality of ecological revetments 100 are arranged along the bank in the watershed water to form a plurality of ecological revetments at a predetermined interval. The soft raft 110 laid on the surface layer of the ecological slope protection 100 is woven by multiple layers of high molecular polymer fibers, and the soft raft 110 has a larger stable pore size, preferably 0.05-1 cm, and more preferably 0.1-0.5 cm. The aperture can intercept silt in water and connect the silt into blocks in gaps among fibers, thereby providing favorable conditions for plant rooting, all plants not only play a role in landscaping, but also create a suitable growing environment for fish, shrimp and mollusk, form a biosphere with mutual food chains of plants, animals and microorganisms, reestablish original ecology and ensure biological diversity. The plants are aquatic plants including but not limited to tape grass, phalaris arundinacea, alfalfa, ryegrass, cocksfoot, vetiver, and the like.

Furthermore, the soft raft 110 of the present invention can be composed of one or more of non-woven fabrics, geotextiles, ecological bags, etc. woven by using the existing multilayer high molecular polymer fibers, which greatly saves the consumption of resources such as stones, etc. compared with the traditional hard revetment.

As shown in fig. 1, in the present invention, four functional layers are laid on the packing layer of the ecological filter 120 from top to bottom,

the first layer is a soil layer 121 used for supporting the growth of aquatic plants, carrying out heavy metal adsorption, organic matter degradation and nitrogen and phosphorus removal;

the second layer is a regulation layer 122 which is used for supporting the soil layer 121 and carrying out adsorption and fixation on heavy metal, nitrogen, phosphorus and organic matters;

the third layer is a biomass layer 123 for heavy metal adsorption and fixation, organic matter degradation and nitrogen and phosphorus removal.

The fourth layer is an ecological layer 124, which is used for filtering water, intercepting soil, avoiding soil loss and blocking a water outlet pipeline.

In the invention, the soil layer 121 is laid on the first layer, and the thickness of the soil layer 121 is 35-50cm, so that rooting growth of aquatic plants is facilitated.

In a preferred embodiment, carbon is added to the soil layer 121 and earthworms are added to the soil layer 121 to convert the soil layer 121 into an earthworm bed. The earthworm feeding density is 8 g-12 g (earthworm)/(L filler). Wherein, the carbon includes but is not limited to wood chips, mushroom bran, straws and the like.

In a preferred embodiment, the earthworms are selected from the group consisting of red Taihu earthworms and Thielavia virginiana, and the new improved earthworm species have significant flooding tolerance and are more resistant to soiling.

The introduction of the earthworms, the introduction of the microorganisms in the soil and the introduction of the microorganisms in the biological layer 123 facilitate the ecological filter 120 to fully utilize the synergistic effect of the earthworms and the microorganisms, and the functions of increasing the air permeability, the water permeability, the organic matter ingestion and the like of the earthworms, so that the sewage treatment can be performed better and more effectively. The earthworms can not only degrade organic matters in the ecological filter 120, but also promote C, N, P transformation and mineralization through the grinding of the sand sacs, the biochemical action of intestinal tracts and the synergistic action of the earthworms and microorganisms, but have the main functions of mechanical loosening and digestion in the soil active layer, play a role in physically cleaning the filter bed and prevent soil hardening and blocking. The movement of the earthworms in the filter tank can also effectively improve the microbial quantity and the microbial activity and promote the anaerobic decomposition and transformation of organic substances.

In the invention, the second layer is paved with an adjusting layer 122, wherein the adjusting layer 122 is composed of natural zeolite, limestone and activated carbon, and the mixing ratio is 1:1: 1; the thickness of the adjusting layer 122 is 20-30 cm.

The natural zeolite, limestone and active carbon have more pore structures and corresponding adsorption capacity, and especially the active carbon has strong adsorption capacity; the molecular structure framework of the natural zeolite has greater advantages in the adsorption capacity of the natural zeolite to heavy metals, ammonia nitrogen and organic matters in the ore material; the limestone has an effective regulating effect on the acidity and alkalinity of the water body, and is beneficial to the growth of upper plants and the activity of microorganisms in the third biological layer 123. The natural zeolite is increased, the amount of the active carbon and the limestone is correspondingly reduced, and the adsorption capacity to pollutants is reduced; the amount of the activated carbon is increased, the amounts of the natural zeolite and the limestone are correspondingly reduced, and although the adsorption capacity is improved, the supporting capacity for the soil layer 121 and the adjusting capacity for the pH value of the water body are reduced; the amount of limestone is increased, the amounts of natural zeolite and activated carbon are correspondingly reduced, the pH value adjusting capability of the water body is improved, but the adsorption capability is reduced.

The particle size of the natural zeolite, limestone and active carbon in the adjusting layer 122 is 0.2-2.0 cm. The ecological filter 120 is a measure for effectively reducing or removing pollutants in the leachate under three synergistic effects of physics, chemistry and biology, and the moderate dissolved oxygen is beneficial to the physical, chemical and biological reactions. The particle size of the filler in the adjusting layer 122 is selected in consideration of coordination of gas circulation and pollutant adsorption, so that poor gas circulation caused by too dense filler accumulation is avoided in the range, and the adjusting layer has good adsorption capacity.

In the invention, the third layer is laid with a biological layer 123, and the filler is activated carbon loaded with bacteria, namely biological activated carbon. The thickness of the bio-layer 123 is 20-40 cm.

The supported bacteria include nitrobacteria (nitrite bacteria and nitrate bacteria) and phosphorus-accumulating bacteria, which can be fixed on the biochar by a carrier combination method (such as Chenohui, Zhangfu, etc., deodorization synergistic effect (English) J. science and technology and engineering of the biochar and immobilized microorganisms thereof on the garbage compost, 2013,13(32):9592 one 9597+9618, the recording method) and the nitrogen and phosphorus removal efficiency is improved by the combination of biochar adsorption and microorganism metabolism.

The phosphorus accumulating bacteria can synthesize polyphosphate to accumulate in bacterial cells under aerobic condition, and release phosphorus under anaerobic condition, and the aerobic phosphorus accumulating amount is larger than the anaerobic phosphorus releasing amount, so the phosphorus content in the percolate can be effectively controlled by adding the phosphorus accumulating bacteria. The nitrifying bacteria can oxidize ammonia nitrogen into nitrite and nitrate forms, the denitrifying bacteria can utilize organic matters and nitrate to carry out denitrifying denitrification, and the two are combined to realize nitrogen removal.

The particle size of the biological activated carbon is 0.10-0.80 cm, and the particle size is favorable for realizing coexistence of an aerobic environment and an anoxic environment and realization of functions of microorganisms.

In the invention, the ecological layer 124 is laid on the fourth layer, and the filler in the ecological layer 124 is one or more of waste materials such as fine sand, broken stone, steel slag, coal slag, construction waste, waste gypsum and the like. The ecological layer 124 is 20-40cm thick; the particle size of the filler is 0.1-5.0 cm.

The waste materials which are idle in life and difficult to treat are used in ecological construction, so that the utilization value of the materials is improved, and the construction cost of the ecological slope protection 100 is reduced. When the ecological layer 124 is filled with materials with adsorption performance, such as fine sand, broken stone, coal cinder, construction waste, waste gypsum and the like, the ecological layer 124 has a function of adsorbing heavy metals and organic matters besides a filtering function.

In the invention, a supporting layer 125 is laid below the packing layer and used for supporting the packing on the upper layer, the packing is cobblestones, and the particle size of the cobblestones is 5.0-10.0 cm. The thickness of the supporting layer 125 is 10-15 cm.

The cobblestones are weathered rocks which have a pore structure and the performance of adsorbing pollutants, so that heavy metal and organic matters can be adsorbed and fixed; meanwhile, the water body treated by the four layers of fillers is discharged from the water discharge pipe 150 at the bottom of the ecological slope protection 100 due to the high particle size.

As shown in fig. 3 and 4, in the present invention, basin water is introduced into the ecological slope protection 100 through a water pump via a water distribution pipe 130, the water distribution pipe 130 is installed in the surface layer (which represents the outside of the soil layer 121) and the soil layer 121 of the ecological slope protection 100, the water distribution pipe 130 is a PVC pipe, and water outlet holes of 0.1-0.5 cm are distributed on the pipe diameter, so that water infiltrating irrigation enters the novel ecological slope protection 100. The periphery of the water distribution pipe 130 is wrapped with the rock particles by the geotextile, the outer layer of the geotextile is soil, and the geotextile is provided with the filtration-bluestone support, so that the possibility that moist soil blocks a water outlet hole is avoided.

In a preferred embodiment, an aeration pipe 140 is disposed beside the water distribution pipe 130 installed in the soil layer 121, and an external fan performs aeration. The aeration pipe 140 is arranged beside the water distribution pipe 130, and the aeration pipe 140 effectively solves the oxygenation problem of the basin water under the ecological slope protection 100, and is beneficial to the survival of the plant-earthworm-aerobic microorganism and the removal of organic pollutants (mainly BOD), the nitrification of nitrogen-containing substances and the dephosphorization of phosphorus-containing substances in the basin water.

Further, the aeration pipe 140 and the water distribution pipe 130 are respectively wrapped in the gravel-geotextile.

The aeration pipe 140 can also be a PVC pipe, and air outlets of 0.05-0.2 cm are distributed on the pipe diameter.

In the present invention, a waterproof sheet (i.e., a waterproof sheet) with good sealing performance is used to isolate the ecological slope protection 100 from water in the external watershed.

As shown in fig. 4, in a preferred embodiment of the present invention, the ecological slope protection 100 is a modular structure, i.e. the water-proof plate is made into the body of the ecological filter 120, so that the body can be assembled and placed at the water treatment site, and the filling materials are sequentially added, and one body correspondingly forms one ecological filter 120. Each ecological slope protection 100 can comprise one or more ecological filter tanks 120, and preferably each ecological slope protection 100 comprises at least two ecological filter tanks 120.

Because the lower flow velocity is higher than the upper flow velocity in some water bodies and the amount of sediment in the lower portion is large and thick, if the ecological filter tank 120 is tightly stacked to construct the ecological slope protection 100, the flow velocity of the lower water body may be seriously inhibited, which affects the water flow exchange at the two sides of the ecological slope protection 100 and increases the impact strength of the ecological slope protection 100. Therefore, the plurality of ecological filters 120 are layered and stacked in rows, the ecological filters 120 on each row are aligned, and a set pore, such as 5-10 cm, is reserved between adjacent ecological filters 120 on each layer.

In a preferred embodiment, in order to facilitate the laying and fixing of the soft mattress 110, the uppermost ecological filter chamber 120 is designed to be stepped, so that a weight can be placed on the stepped portion to press and fix the soft mattress 110.

In a preferred embodiment, in the same row of ecological filter chambers 120, the water outlet pipe in the upper layer of ecological filter chamber 120 is connected with the water distribution pipe 130 of the lower layer of ecological filter chamber 120, and the drainage basin water treated by the upper layer is introduced into the soil layer 121; the aeration pipe 140 in the upper ecological filter 120 is connected with the aeration pipe 140 of the lower ecological filter 120, so that the gas passes through the upper ecological filter 120 and then is introduced into the soil layer 121 of the lower ecological filter 120; preferably, the diameter of the aeration pipe 140 in the next ecological filter 120 is larger than that of the aeration pipe 140 in the previous ecological filter 120, so as to facilitate gas transmission.

In the invention, the novel ecological slope protection 100 adopts a modular structure, the drain pipe 150 at the bottom end of the ecological filter 120 can be spliced with the water distribution pipe 130 of the previous ecological filter (120) to realize the series connection of multi-stage units, all the components such as the biological filter body, the water distribution pipe 130, the aeration pipe 140, the drain pipe 150 and the like can be prefabricated, and then the components are spliced and assembled on site and buried under a slope, so the installation is simple and convenient, the construction speed is greatly improved, the facility equipment of water treatment in a drainage basin is realized, and the industrialized production is facilitated and the subsequent maintenance and the filler replacement are also facilitated.

In a preferred embodiment, a wire cage is sleeved on the periphery of the tank body of each ecological filter tank 120, so that the force application points to the ecological filter tanks 120 are increased, and the ecological filter tanks 120 are replaced and the like by applying force to the wire cages.

In a preferred embodiment, since the water quality in the center of the basin is generally better than that on the bank, the water on the bank will be treated by more layers of the ecological filter tanks 120 than the water in the center of the basin, for example, the water on the bank will be treated by the three layers of the ecological filter tanks 120, and the water in the center of the river will be treated by the two layers of the ecological filter tanks 120.

For this reason, the height of the ecological slope protection 100 is gradually reduced from the bank side to the water body, so that the water from the center of the basin and the water from the bank side can be respectively input into the ecological filter 120 with different heights for treatment.

Aiming at the difference of the water quality of the center and the bank of the basin, the basin water is comprehensively up to the standard of high effluent water quality through different water taking points and the respective treatment of the ecological filter tanks 120 with different layers.

After a period of water treatment, the biofilter 120 is repaired. The repairing method comprises the following steps: and taking out the uppermost ecological filter chamber 120 in the ecological slope protection 100, lifting the next ecological filter chamber 120, namely the second ecological filter chamber, to the position of the uppermost ecological filter chamber 120, and filling the newly-charged ecological filter chambers 120 to the position of the original second ecological filter chambers 120. The ecological filter 120 below the second layer has better water quality than the upper layer, so that the ecological filter 120 can be directly replaced by a new ecological filter 120 after longer-time water treatment.

In a preferred embodiment, the ecological slope protection 100 is a forward-projecting slope protection, and the direction in which the ecological slope protection 100 extends into the water body is approximately perpendicular to the shoreline, i.e., the included angle α between the ecological slope protection 100 and the shoreline is 85 ° or more and 95 ° or less; or the ecological slope protection 100 is an upward-projecting slope protection, and in the water flow direction, the included angle alpha between the direction of the ecological slope protection 100 extending into the water body and the bank side line is more than 95 degrees and less than 175 degrees; or the ecological slope protection 100 is a downward-projecting slope protection, and in the water flow direction, the included angle alpha between the direction of the ecological slope protection 100 extending into the water body and the bank side line is more than 5 degrees and less than 85 degrees. In lakes or watersheds with slower water flow, the included angle between the ecological slope protection 100 and the shoreline can be in any range; in open type basins or sections with more urgent water flow, the extension direction design is carried out according to specific environments so as to achieve the functions of energy dissipation and wave dissipation.

In a further preferred embodiment, in a lake or a river basin with a relatively slow water flow, the upper slope protection and the lower slope protection are arranged in sequence, and a gathering port is formed at the opposite position of the two ecological slope protections 100. The existence of the convergence port enables the sediment and the phytoplankton to enter through the convergence port and stay in the area enclosed by the two ecological revetments 100 when the water waves or the water flow carry suspended matters such as the sediment and the like and organisms such as the phytoplankton such as green algae and the like to impact the ecological revetments 100. The semi-openness of the gathering port enables silt, phytoplankton and the like to continuously flow in, and sediment or stay at the edge of a shoreline and is difficult to completely leave, so that the shielding of the phytoplankton on the water surface in an external water body is reduced, meanwhile, the sediment and the siltation of suspended matter such as silt and the like are beneficial to the growth of non-phytoplankton in the edge of the shoreline, the non-phytoplankton is induced and driven to recover, the growth of the phytoplankton is inhibited, and the purification processes of nitrogen and phosphorus removal and the like.

In a preferred embodiment of the present invention, a conditioning tank is constructed near the ecological slope protection 100 on the bank side, and the conditioning tank introduces basin water to be treated and then transfers supernatant to the ecological slope protection 100.

The adjusting tank comprises a fermentation tank 210, a sedimentation tank 220 and an extraction tank 230, basin water is introduced into the fermentation tank 210, the cyanobacteria salvaged from the basin is fermented, and the fermentation liquor is used as an organic fertilizer for fertilizer maintenance of the bank eucalyptus; a water inlet of the sedimentation tank 220 is provided with a grid or a filter screen, basin water for removing floating objects, suspended matters and aquatic organisms is introduced, and supernatant after sediment sedimentation is transmitted to each upper ecological filter 120; basin water is introduced into the extraction tank 230, the collected eucalyptus leaves are put into the extraction tank 230 to prepare a eucalyptus leaf leaching liquor, and the obtained eucalyptus leaf leaching liquor is directly introduced into the basin water.

From the above, the adjusting tank is a multifunctional adjusting tank, and only one of the functional units can be implemented, for example, only the sedimentation tank 220 is started to perform sedimentation treatment on the basin water.

The adjusting tank is constructed, plays a role in regulating and controlling blue-green algae fertilization, basin water retreatment and allelochemical release, and is an effective auxiliary means for controlling the blue-green algae in the basin water.

Another objective of the present invention is to provide the above system for controlling the growth of blue algae in water area, which comprises an ecological protection slope 100 constructed at the land-water cross zone of the water bank of the water area, and a regulating reservoir constructed at the bank side adjacent to the ecological protection slope 100;

the slope body of the ecological slope protection 100 extends into the basin water, the surface layer of the slope body is paved with a soft body row 110, the lower part of the soft body row 110 is an ecological filter tank 120, the ecological filter tank 120 isolates the basin water through a tank body, a filler layer and a bearing layer 125 are filled in the ecological filter tank 120, the basin water is introduced into the ecological filter tank 120, the introduced basin water is subjected to pollutant treatment through the filler layer to reduce the eutrophication degree of the basin water, the filler layer is supported through the bearing layer 125, and the ecological slope protection 100 is discharged from the treated basin water through the bearing layer 125;

the basin water is introduced into the regulating tank, and after treatment, the supernatant is transmitted to the ecological slope protection 100.

In a preferred embodiment, the filler layer of the ecological filter 120 is laid with four functional layers from top to bottom,

the first layer is a soil layer 121 used for supporting the growth of aquatic plants, carrying out heavy metal adsorption, organic matter degradation and nitrogen and phosphorus removal; preferably, the thickness of the soil layer 121 is 35-50 cm;

the second layer is a regulation layer 122 which is used for supporting the soil layer 121 and carrying out adsorption and fixation on heavy metal, nitrogen, phosphorus and organic matters; preferably, the adjusting layer 122 is composed of natural zeolite, limestone and activated carbon, the mixing ratio is 1:1:1, and the particle size of the filler is 0.2-2.0 cm; the thickness of the adjusting layer 122 is 20-30 cm;

the third layer is a biomass layer 123 for heavy metal adsorption and fixation, organic matter degradation and nitrogen and phosphorus removal; the filler is activated carbon loaded with bacteria (i.e., biological activated carbon). The particle size of the filler in the biological layer 123 is 0.10-0.80 cm, and the thickness of the biological layer 123 is 20-40 cm.

The fourth layer is an ecological layer 124 used for filtering water and intercepting soil to avoid soil loss; the filler in the ecological layer 124 is one or more of waste materials such as fine sand, broken stone, steel slag, coal slag, building waste, waste gypsum and the like. The grain diameter of the filler in the ecological layer 124 is 0.1-5.0 cm, and the thickness of the ecological layer 124 is 20-40 cm.

In a more preferred embodiment, carbon is added to the soil layer 121, and earthworms are added to the soil layer 121 to convert the soil layer 121 into an earthworm bed. The earthworm feeding density is 8 g-12 g (earthworm)/(L filler).

In a further preferred embodiment, the basin water is introduced into the ecological slope protection 100 through a water distribution pipe 130 by a water pump, the water distribution pipe 130 is respectively installed on the surface layer of the ecological slope protection 100 and the soil layer 121, the water distribution pipe 130 is a PVC pipe, and water outlet holes of 0.1-0.5 cm are distributed on the pipe diameter.

An aeration pipe 140 is arranged beside the water distribution pipe 130 arranged in the soil layer 121 and is externally connected with a fan for aeration. The aeration pipe 140 can also be a PVC pipe, and air outlets of 0.05-0.2 cm are distributed on the pipe diameter.

The aeration pipe 140 and the water distribution pipe 130 are respectively wrapped in a rock sub-geotextile, and the outer layer of the geotextile is soil.

In a further preferred embodiment, the ecological slope protection 100 is of a modular structure, one ecological filter 120 is correspondingly formed in one pool body, each ecological slope protection 100 may include one or more ecological filter 120, and preferably, each ecological slope protection 100 includes at least two ecological filter 120. When a plurality of ecological filter tanks 120 are included, the ecological filter tanks 120 are layered and stacked in rows, the ecological filter tanks 120 on each row are aligned, and a set pore is reserved between adjacent ecological filter tanks 120 on each layer.

Preferably, in the same row of the ecological filter chambers 120, the water outlet pipe in the upper layer of the ecological filter chambers 120 is connected with the water distribution pipe 130 of the lower layer of the ecological filter chambers 120, and the drainage basin water treated by the upper layer is introduced into the soil layer 121; the aeration pipe 140 in the upper ecological filter 120 is connected with the aeration pipe 140 of the lower ecological filter 120, so that the gas passes through the upper ecological filter 120 and then is introduced into the soil layer 121 of the lower ecological filter 120; preferably, the diameter of the aeration pipe 140 in the next ecological filter 120 is larger than that of the aeration pipe 140 in the previous ecological filter 120, so as to facilitate gas transmission.

In a further preferred embodiment, a wire cage is sleeved on the periphery of the tank body of each ecological filter tank 120.

In a further preferred embodiment, the height of the ecological protection slope 100 gradually decreases from the shore to the water body, so that the water from the center of the basin and the water from the shore can be respectively input into the ecological filter tanks 120 with different heights for treatment.

In a further preferred embodiment, in a lake or a river basin with a relatively slow water flow, the upper slope protection and the lower slope protection are arranged in sequence, and a gathering port is formed at the opposite position of the two ecological slope protections 100.

In a preferred embodiment, the adjusting tank comprises a fermentation tank 210, a sedimentation tank 220 and an extraction tank 230, the fermentation tank 210 introduces drainage basin water, the cyanobacteria fished from the drainage basin is subjected to fermentation treatment, and the fermentation liquor is used as an organic fertilizer for fertilizer maintenance of the eucalyptus ashore; a water inlet of the sedimentation tank 220 is provided with a grid or a filter screen, basin water for removing floating objects, suspended matters and aquatic organisms is introduced, and supernatant after sediment sedimentation is transmitted to each upper ecological filter 120; basin water is introduced into the extraction tank 230, the collected eucalyptus leaves are put into the extraction tank 230 to prepare a eucalyptus leaf leaching liquor, and the obtained eucalyptus leaf leaching liquor is directly introduced into the basin water.

Examples

The flow rate of the river is 3000m³D, hydraulic load 0.5m³/(m²D). As shown in figure 1 and figure 2, 10 novel ecological revetments need to be alternately transformed along two banks of a river, and each novel ecological revetments are treated by 6m³The basin water. Meanwhile, eucalyptus strips are planted along two banks of the river.

As shown in fig. 4, each novel ecological slope protection 100 is composed of two primary ecological filter tanks (the uppermost ecological filter tank), two secondary ecological filter tanks (the middle ecological filter tank), and one tertiary ecological filter tank (the bottom ecological filter tank), and is arranged in two rows and three rows, wherein the primary ecological filter tanks are irregularly stepped, the size of the bottom plate is 2m 1.5m, the total height is 1.5m, the height of the step is 1m, the depth of the step is 0.75m, and the shell of the secondary/tertiary ecological filter tanks is an uncovered container with the height of 2m 1.5 m. Riverway bank side water flows through the first row of ecological filter tanks, and riverway center water flows through the second row of ecological filter tanks. The ecological filter 120 is formed by installing glass fiber reinforced plastics with better sealing performance, no water leakage and no water seepage on site. The periphery of the tank body of each ecological filter tank is sleeved with a metal wire cage.

The water is fed for 6 hours every day by adopting an intermittent water feeding mode, and the bottom of each ecological filter tank is provided with a water discharge pipe 150 matched with a water distribution pipe 130 with the same pipe diameter. At the bottommost end of the whole ecological slope protection, two water discharge pipes are converged into a large water outlet pipe and then discharged back into a river. And corresponding aeration pipes are arranged beside the water distribution pipes.

The surface layer of the ecological slope protection 100 is paved with soft raft 110 spliced by non-woven fabrics, the aperture of the soft raft is 0.05-1 cm, and an ecological filter tank is arranged below the soft raft. Each ecological filter comprises an earthworm bed with the thickness of 35-45 cm, an adjusting layer 122 (composed of natural zeolite, limestone and active carbon and the mixing ratio is 1:1:1, the particle size is 0.2-2.0 cm), a biological layer 123 (composed of biological active carbon loaded with nitrite bacteria, nitrate bacteria and phosphorus-accumulating bacteria and the particle size is 0.10-0.80 cm) with the thickness of 20-40cm, an ecological layer 124 (composed of fine sand, broken stone and coal slag and the particle size is 0.1-5.0 cm) with the thickness of 20-40cm and a supporting layer 125 (composed of pebbles with the particle size of 5.0-10.0 cm) with the thickness of 10-15 cm. Taihu red earthworms are put into the earthworm bed, the density of the earthworms is 10g (earthworms)/(L filler), and the earthworm bed is an earthworm moving area.

The bottom of each filter is provided with a drain pipe 150, and the drain pipe 150 is in seamless butt joint with the water distribution pipe 130. The aeration pipe 130 is arranged at the edge of the water distribution pipe 130, so that oxygen required by organic matter decomposition can be fully supplemented in the process of dripping water in a flow area. The water distribution pipes 130 are respectively installed in the surface layer of the ecological slope protection 100 and the soil layer 121, the water distribution pipes 130 are PVC pipes, water outlet holes of 0.1-0.5 cm are distributed on the pipe diameters, and the periphery of the water distribution pipes is wrapped by geotextile to form green stones, so that water infiltrating irrigation enters the novel ecological slope protection 100.

A regulating reservoir is constructed on the bank side near the ecological slope protection 100. The adjusting tank comprises a fermentation tank 210, a sedimentation tank 220 and an extraction tank 230, basin water is introduced into the fermentation tank 210, the cyanobacteria salvaged from the basin is fermented, and the fermentation liquor is used as an organic fertilizer for fertilizer maintenance of the bank eucalyptus; a water inlet of the sedimentation tank 220 is provided with a grid or a filter screen, basin water for removing floating objects, suspended matters and aquatic organisms is introduced, and supernatant after sediment sedimentation is transmitted to each upper ecological filter 120; basin water is introduced into the extraction tank 230, the collected eucalyptus leaves are put into the extraction tank 230 to prepare a eucalyptus leaf leaching liquor, and the obtained eucalyptus leaf leaching liquor is directly introduced into the basin water.

After the ecological revetment is built and runs for 9 months (the adjusting pond only uses the sedimentation pond therein), the overflowing water body near the ecological revetment is detected for a plurality of times in winter (the next 3 months), and the result shows that the average removal rate of main pollutants in the overflowing water by 10 ecological revetments is as follows: 70% of suspended particulate matter, 65% of chemical oxygen demand, 59% of five-day biochemical oxygen demand, 65.7% of total phosphorus, 69.1% of ammonia nitrogen and 52.2% of nitrite nitrogen; the dissolved oxygen increased by 25%.

Examples of the experiments

Experimental example 1

Preparing a eucalyptus leaching solution: 1) cutting eucalyptus leaves into small pieces; 2) drying the eucalyptus leaves in a drying oven at 40 ℃ until the weight is balanced; 3) pulverizing the dried eucalyptus leaves by a pulverizer until the diameter of the powder is less than 200 meshes; 4) putting the powder into water according to the proportion of 1g/40mL for leaching; 4) performing ultrasonic treatment for 30min every 24h for 7 days; 5) filtering with gauze to obtain folium Eucalypti Globueli extractive solution.

Testing the algae inhibition capacity of the eucalyptus leach liquor: 100mL BG-11 culture medium and 1mL blue algae in logarithmic phase are added into a 250mL conical flask, after the blue algae are adapted to a new culture solution for two days, 0.4mL and 25g of leaching liquor are added into the new culture solution, the concentration of the leaching liquor in the algae solution reaches 100mg (dry weight of leaves)/(L), and the blue algae density and blue algae inhibition rate of the 1 st, 2 nd, 3 th, 4 th and 5 th days of the experiment are measured, and the result is shown in figure 5. 0.8mL and 25g/L of leaching liquor is added into the algae solution, so that the concentration of the leaching liquor in the algae solution reaches 200mg (dry weight of leaves)/(L), and the blue algae density and blue algae inhibition rate of the No. 1, 2, 3, 4 and 5 blue algae in the experiment are measured, and the result is shown in figure 6.

As can be seen from FIG. 5 and FIG. 6, the leaching solution of eucalyptus leaves has a strong inhibitory effect on blue algae, and the inhibitory rate is related to the amount of the leaching solution of eucalyptus leaves. The dosage is 100mg/L, and the algae inhibition rate can reach 40% on the 5 th day of the experiment. The dosage is 200mg/L, and when the experiment is carried out to the 4 th day, the algae inhibiting rate can reach more than 95 percent.

Experimental example 2

The eucalyptus seedlings (Guangyu No. 29) are purchased from Guangxi province and are about 30cm long. Two identical experimental devices containing 4L BG11 culture medium were prepared, and blue algae, blue algae and eucalyptus were added, respectively. From the start of the experiment, the density of blue algae, soluble organophosphorus SPR (ultraviolet spectrophotometry), nitrate nitrogen NO were monitored for 1, 3, 6, 9 and 12 days of culture₃ ^-N (ultraviolet spectrophotometry). The results of the experiment are shown in FIG. 7.

As can be seen from the graph 7, allelochemicals for inhibiting the growth of blue algae can be secreted in the growth process of eucalyptus seedlings, and nutrient salts such as nitrogen, phosphorus and the like in water can be rapidly absorbed. From the third day, the density of the blue algae in the blue algae and eucalyptus seedling sample is rapidly reduced until the density is lower than the detection limit. The situation shows that allelochemicals for inhibiting the growth of blue algae can be secreted in the growing process of the eucalyptus seedlings, so that the blue algae die greatly. The concentration of nitrogen and phosphorus in the blue algae and eucalyptus seedling sample water body is in a descending trend along with the progress of the experiment, and 1.26mg of phosphorus and 12.24mg of nitrogen are reduced in 12 days. The eucalyptus is proved to absorb nutrient salts such as nitrogen, phosphorus and the like into the body for growth and purify the water body.

The invention has been described in detail with reference to specific embodiments and/or illustrative examples and the accompanying drawings, which, however, should not be construed as limiting the invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, which fall within the scope of the present invention. The scope of the invention is defined by the appended claims.

Claims

1. A method for controlling the growth of blue algae in a water area, the method comprising: planting trees in and/or along the shore of the watershed water;

the tree is eucalyptus, pollutants are absorbed or fixed through the root system of the tree, and the growth of blue algae is inhibited;

the method also comprises collecting folium Eucalypti Globueli, and adding folium Eucalypti Globueli or folium Eucalypti Globueli leaching solution into watershed water; wherein the folium Eucalypti Globueli leaching solution is water leached product;

an ecological protection slope (100) is constructed at a land-water staggered zone on the bank side of the basin water, a slope body of the ecological protection slope (100) extends into the basin water, a soft body row (110) is laid on the surface layer of the ecological protection slope, an ecological filter tank (120) is arranged at the lower part of the soft body row (110), the ecological filter tank (120) isolates the basin water through a sealed tank body, a filler layer and a bearing layer (125) are filled in the ecological filter tank (120), the basin water is introduced into the ecological filter tank (120), pollutant treatment is carried out on the introduced basin water through the filler layer, the eutrophication degree of the basin water is reduced, the filler layer is supported through the bearing layer (125), and the treated basin water is discharged into the ecological protection slope (100) through the bearing layer (125);

the soft mattress (110) laid on the surface layer of the ecological slope protection (100) is woven by a plurality of layers of high molecular polymer fibers, and the soft mattress (110) has larger stable pore diameter.

2. The method of claim 1, wherein the soft body row (110) has a stable pore size of 0.05-1 cm.

3. The method of claim 1, wherein the packing layer of the ecological filter tank (120) is laid with four layers from top to bottom,

the first layer is a soil layer (121) which is used for supporting the growth of aquatic plants and carrying out heavy metal adsorption, organic matter degradation and nitrogen and phosphorus removal;

the second layer is an adjusting layer (122) which is used for supporting the soil layer (121) and carrying out adsorption and fixation on heavy metal, nitrogen, phosphorus and organic matters; the adjusting layer (122) is composed of natural zeolite, limestone and activated carbon;

the third layer is a biomass layer (123) used for heavy metal adsorption and fixation, organic matter degradation and nitrogen and phosphorus removal;

the fourth layer is an ecological layer (124) used for filtering water and intercepting soil; the filler of the ecological layer (124) is one or more of waste materials such as fine sand, broken stone, steel slag, coal slag, building waste, waste gypsum and the like.

4. The method according to claim 3, characterized in that the filler of the biolayer (123) is activated carbon loaded with bacteria.

5. The method according to claim 3, characterized in that earthworms are put in the soil layer (121) at a density of 8-12 g (earthworms)/(L filler).

6. The method of claim 3, wherein the basin water is introduced into the ecological slope protection (100) through a water pump via water distribution pipes (130), the water distribution pipes (130) are respectively installed in the surface layer and the soil layer (121) of the ecological slope protection (100), the water distribution pipes (130) are PVC pipes, water outlet holes with the diameter of 0.1-0.5 cm are distributed on the pipe diameters, and water is infiltrated and irrigated into the novel ecological slope protection (100).

7. The method of claim 6, wherein the water distribution pipes (130) are installed in the soil layer (121) and aeration pipes (140) are arranged beside the water distribution pipes (130), and are aerated by an external fan; wherein, aeration pipe (140) are the PVC pipe, distribute 0.05 ~ 0.2 cm's venthole on the pipe diameter.

8. The method of claim 6, wherein the periphery of the aeration pipe (140) and the water distribution pipe (130) is wrapped with a geotextile around the gravel.

9. The method of claim 6, wherein the ecological slope protection (100) adopts a modular structure, the waterproof sheet material is made into a pool body of the ecological filter pool (120), and then the pool body can be assembled and placed on a water treatment site, and the fillers are added in sequence, and one pool body correspondingly forms one ecological filter pool (120);

each ecological slope protection (100) can comprise one or more ecological filter tanks (120).

10. The method according to claim 9, wherein each ecological slope protection (100) comprises at least two ecological filter tanks (120).

11. The method of claim 9, wherein the plurality of ecological filter chambers (120) are stacked in layers and columns, wherein the ecological filter chambers (120) are aligned on each column, and wherein a set pore is left between adjacent ecological filter chambers (120) on each layer.

12. The method according to claim 9, characterized in that in the same row of the ecological filter tanks (120), the water outlet pipe in the upper layer of the ecological filter tank (120) is connected with the water distribution pipe (130) of the lower layer of the ecological filter tank (120), and the drainage basin water treated by the upper layer of the ecological filter tank (120) is introduced into the soil layer (121);

the aeration pipe (140) in the upper layer of the ecological filter pool (120) is connected with the aeration pipe (140) of the next layer of the ecological filter pool (120), so that the air passes through the upper layer of the ecological filter pool (120) and then is introduced into the soil layer (121) of the next layer of the ecological filter pool (120).

13. The method according to claim 12, wherein the diameter of the aeration pipe (140) in the next ecological filter (120) is larger than that of the aeration pipe (140) in the previous ecological filter (120).

14. The method as claimed in claim 9, wherein a wire cage is sleeved on the periphery of the tank body of each ecological filter tank (120);

the shoreside water will be treated by more layers of ecological filter tanks (120) than the basin core water.